Spacer fabric treated wtih c6 based perfluoroalkyl polymer and method of preparing thereof

ABSTRACT

The present invention relates in general to treated spacer fabrics and a method of preparing such spacer fabrics and more particularly to a spacer fabric being treated for imparting the spacer fabric with at least one or all of the properties selected from good flame retardancy, good oil repellency, high spray rating and low volatile emissions. Furthermore, the invention relates to the use of a specific liquid treating composition for preparing a treated spacer fabric having at least one or all of the properties selected from good flame retardancy, good oil repellency, high spray rating and low volatile emissions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to in the U.S. National Phase PatentApplication based on International Application Serial No.PCT/EP2013/066661 filed Aug. 8, 2013, the disclosure of which is herebyexplicitly incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to treated spacer fabrics and amethod of preparing such spacer fabrics and more particularly to aspacer fabric being treated for imparting the spacer fabric with atleast one or all of the properties selected from good flame retardancy,good oil repellency, high spray rating and low volatile emissions.Furthermore, the invention relates to the use of a specific liquidtreating composition for preparing a treated spacer fabric having atleast one or all of the properties selected from good flame retardancy,good oil repellency, high spray rating and low volatile emissions.

2. Description of the Related Art

Spacer fabrics are three-dimensional fabrics, which are available indifferent executions and material thicknesses. They provide excellentproperties such as a low weight, durable elasticity, springiness andtheir climate effect. This material is used, for example, as automotivetextile in climatic and ventilated seats, seat covers, head liners,instrument and door panels as well as in composite constructions or asconsumer textile in mattresses and furniture or in technical clothingand shoes.

If used in the automotive industry spacer fabrics are required tofurther provide specific properties like good oil repellency, high sprayrating, good flame retardancy and low volatile emissions. Especially,good flame behavior and low volatile emissions are mandatoryrequirements for spacer fabrics when used in the automotive industrytoday. Furthermore, good oil repellency and high spray rating aredesired requirements for such spacer fabrics because of their betterprocessability in the automotive industry. Recently, so-called C8fluorocarbon polymers have been used as state-of-the-art treatingmaterial for imparting spacer fabrics used in the automotive industrywith the required oil repellency and spray rating. To achieve the alsorequired flame retardancy the spacer fabrics where and still areadditionally treated with flame retardants.

Prior to the breakthrough of fluorocarbon polymers, water repellentcoatings were only achievable by wax emulsions or silicone applications,both of which were available in water borne emulsions or in solventsolutions. The early developments of fluorocarbons were only availablein solvent based solutions, generally hazardous solvents, and of courseenvironmental implications have led to the development of water basedfluoropolymer emulsions, which are much safer and easier to handle. Thefluoropolymers have outclassed the performance characteristics ofsilicones and waxes as they are exceptional at performing theirfunctions at much lower levels, thereby reducing volume and costfactors. Recent concerns over the past few years have highlightedspecific products associated with fluoropolymers, namely PFOA and PFOS(Perfluorooctanoic acid and Perfluorooctane Sulphonate, respectively);(source: www.texchem.co.uk/fluoroinfo.html).

PFOA is an abbreviation for Perfluorooctanoic Acid. C8 telomer is achemical compound that contains 8 carbon atoms and 17 fluorine atoms.Many water and oil repellent products used for long term protection oftextiles are based on C8 telomers. In manufacturing a trace amount ofPFOA can be generated as an unintended by-product in C8-based repellentmaterials. In 2000, the U.S. Environmental Protection Agency (EPA)became concerned about data that indicated that PFOA is found in humanblood in the general population. During the 90's it had become apparentthat these materials had spread throughout the global environment andthat they were accumulating in biological systems. Since then, the EPAand the industry have conducted studies, and collected and sharedinformation regarding PFOA. In January 2006, the U.S. EnvironmentalProtection Agency (EPA) approached the eight largest fluorocarbonproducers and requested their participation in the 2010/15 PFOAStewardship Program, and their commitment to reduce PFOA and relatedchemicals globally in both facility emissions and product content 95percent by 2010, and 100 percent by 2015. As a result of the EPArecommendation, all fluorochemical companies chose to stopmanufacturing, using and selling Perfluorooctanoic Acid (PFOA) and C8telomer-based water and oil repellent products by the end of 2012. Infact they are transitioning even earlier than the original target, sothat getting C8-based materials is currently impossible. The C6/C8discussion is complex. Reducing PFOA makes sense. At the same time,moving from C8 to C6 may require using 50% more fluorochemical insimilar formulations to get the same performance; (source:www.greenshieldfinish.com/pdf/C8toC6ConversionSummary.pdf).

According to “http://marketplace.yet2” chemicals containingperfluoroalkyl (CF₂)_(n)-sections or tails have been used in industry toprovide to substrate a) resistance to and prevention of staining bysubstances that contain one or more of: oil, grease, organic solvent,and water, b) surfactant properties to help aqueous-based solutionsspread over low surface area surfaces such as oil, c) non-stickproperties. In the last few years, chemicals containing perfluoroalkyltails where n=8 or greater have come under regulatory and marketpressures because of their potential to form PFOA (Perfluoro OctanoicAcid/salts) or the fact that these products contain low levels of PFOAimpurities. Environment Canada and the EPA have stopped approving anynew products that contain C8 or longer perfluorocarbon tails in theirstructure, and California has proposed legislation in place to do thesame. Chemicals containing perfluoroalkyl sections where n<8 aregenerally less efficient, in that most of the chemicals of this type inthe marketplace do not contain reactive functionality capable of formingcovalent bonds. As a result, they are not locked in place on a substratesurface, and can reorient or be removed, causing them to loseefficiency; (source:“http://marketplace.yet2.com/app/list/techpak?id=45112”).

Chemicals containing perfluoroalkyl sections are more expensive thane.g. wax emulsions or silicone applications.

Against this background, it was an object of the present invention toprovide a method of preparing a spacer fabric which is substantiallyfree of PFOA and PFOS, or in general free of any C8 telomer-based waterand oil repellent products, and which nonetheless exhibit the propertieswith respect to oil repellency, spray rating, flame retardancy and lowvolatile emissions required by the automotive industry. Furthermore, inthe light of the relative expensiveness of chemicals containingperfluoroalkyl sections it is a further object of the invention toprovide a cost-efficient method of preparing such a spacer fabric.

SUMMARY OF THE INVENTION

The present invention provides a method of preparing a treated spacerfabric.

The above described object has surprisingly been solved by the presentinvention. This invention is a method of preparing a treated spacerfabric including the steps:

providing a spacer fabric of a thermoplastic polymer;

providing a liquid treating composition comprising one or moreC6-perfluoralkyl based fluoropolymer(s) and a solvent;

treating the spacer fabric by immerging the spacer fabric into a bath ofthe liquid treating composition;

removing excessive treating composition from the treated spacer fabric;

drying the treated spacer fabric; and

fixing the treated spacer fabric.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features and objects of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a flow chart illustrating method steps in accordance with amethod of treating a spacer fabric according to the present invention.

Corresponding reference characters indicate corresponding partsthroughout the several views. Although the exemplification set outherein illustrates an embodiment of the invention, the embodimentdisclosed below is not intended to be exhaustive or to be construed aslimiting the scope of the invention to the precise form disclosed.

DETAILED DESCRIPTION

A “spacer fabric” as herein referred to comprises at least a first andsecond fabric layers that are arranged in an opposing back-to-back,spaced apart relationship with each other. The first and second fabriclayers are interconnected to each other with one or more spacer fibersthat interconnect the first and second fabric layers and define a spacebetween these layers. The spacer fibers comprise a resilient materialthat is able to maintain the space between the fabric layers, whilestill permitting the layers to be reversibly compressed together. As aresult, the spacer fabric provides a relatively light weight andflexible fabric.

In context of the present invention it is preferred that the spacerfabric has a thickness in the range of 1.0 to 7 mm, more preferably inthe range of 1.4 to 6 mm, and most preferably in the range of 1.6 to 5mm. The weight per unit area of the provided spacer fabric used for thepreparation of the treated spacer fabric of the present invention ispreferably in the range of 100 to 500 g/m², more preferably in the rangeof 150 to 400 g/m², and most preferably in the range of 200 to 350 g/m².Furthermore, the spacer fibers that interconnect the first and secondfabric layers are preferably monofil fibers.

The spacer fabric of a thermoplastic polymer provided in step a) of theinventive method and used to prepare the treated spacer fabric is basedon a thermoplastic polymer or at least mainly consists a thermoplasticpolymer. The thermoplastic polymer is preferably selected from the groupconsisting of polyester, polyamid and a combination thereof. Spacerfabrics made of polyester are particularly preferred. “Based on” meansthat the spacer fabric comprises the thermoplastic polymer, for example,as material for the first fabric layer, for the second fabric layer orfor both. Alternatively, the spacer fabric comprises the thermoplasticpolymer as material for the spacer fibers that interconnect the firstand second fabric layers. Also, the spacer fabric can comprise thethermoplastic polymer as material for the spacer fibers and only one ofthe first fabric layer and the second fabric layer. “At least mainlyconsist of” means that the material the spacer fabric is made ofconsists of at least 50% by weight of the thermoplastic polymer.Preferably, at least 90% by weight, more preferably at least 95% byweight or even 100% by weight, of the spacer fabric is made of athermoplastic polymer as defined above.

The treated spacer fabric prepared according to the present invention isparticularly suitable for use in an automobile because of its good flameretardancy and low volatile emissions properties. Furthermore, thetreated spacer fabric prepared according to the present invention isalso particularly suitable for use in an automobile because of its highspray rating and/or good oil repellency properties.

The treated spacer fabric prepared according to the present inventiontypically has an acceptable flame retardancy measured according to FMVSS302 (corresponds to DIN 75200). According to FMVSS 302 the first side ofthe fabric is applied to a flame. It is measured the distance ofburning, the time of burning and the velocity of burning in the machinedirection as well as the cross direction. The same is measured on thesecond side of the fabric. Each of the measurements is repeated 3 times.“Acceptable” here means that at least five of the six measurements onthe first and the second side in cross direction yield a velocity ofburning of less than 100 mm/minute, preferably less than 85 mm/minute,most preferably less than 70 mm/minute.

The treated spacer fabric prepared according to the present inventiontypically has a total emission according to VDA 277 (5 hours, 120° C.)of less than 100 μC/g, preferably less than 90 μC/g.

The treated spacer fabric prepared according to the present inventiontypically has a fogging according to DIN 75201-B (16 hours, 100° C.) ofless than 100 mg, preferably less than 90 mg, most preferably less than80 mg.

The treated spacer fabric prepared according to the present inventiontypically has a smell according to VDA 270-2 (40° C.) of not worse thangrade 3, preferably of grade 2, most preferably of grade 1.

The treated spacer fabric prepared according to the present inventiontypically has a emission of formaldehyde according to VDA 275 of lessthan 3.0 mg/kg, preferably less than 2.5 mg/kg, most preferably lessthan 2.0 mg/kg.

The treated spacer fabric prepared according to the present inventiontypically has a spraytest rating according to AATCC 22 of at least 70,preferably at least 75, most preferably at least 80.

The treated spacer fabric prepared according to the present inventiontypically has an oil repellency rating according to AATCC 118 of atleast 4, preferably at least 5, most preferably at least 6.

“For use in an automobile” as herein referred to means that the treatedspacer fabric prepared according to the invention is used as materialfor the manufacture of car seats, car ceilings, dashboards, carinterior, rear panel shelfs, airbag housings, airbag openings,protection cushions and the like.

“C6-perfluoralkyl based fluoropolymer(s)” as herein referred to is oneor more fluorocarbon derivatives, each derivative comprisingidependently from each other, one or more perfluorohexyl tails and/orone or more perfluoroalkyl (CF₂)_(n)-sections with n=6. TheC6-perfluoralkyl based fluoropolymer(s) may additionally comprise apolymeric backbone bearing more than one groups selected from theperfluorohexyl tails and the perfluoroalkyl (CF₂)_(n)-sections. Thepolymeric backbone may additionally comprise one or more spacer groupsbetween the polymeric backbone and one or more of the the perfluorohexyltails and/or the perfluoroalkyl (CF₂)_(n)-sections. The polymericbackbone may additionally comprise one or more side groups which canbond via any kind of chemical or physical bond to the surface of aspacer fabric. Preferred C6-perfluoralkyl based fluoropolymers usedaccording to the invention are fluorocarbon derivatives comprising morethan one perfluorohexyl tails and a polymeric backbone bearing theperfluorohexyl tails.

A “C8-perfluoralkyl based fluoropolymer” as herein referred to is afluorocarbon derivative comprising one or more perfluorooctyl tailsand/or one or more perfluoroalkyl (CF₂)_(n)-sections with n=8.

A “treated spacer fabric” as herein referred to means a spacer fabricwhich has been treated with any kind of substance, compositions orsolutions. The treating substances or compositions can be in the solid,pulverulent, liquid, viscous or gaseous state. Further, any kind oftreatment is encompassed, e.g. dipping, immerging, spraying or the like.The only proviso is that an amount of such a substance or compositionremains on or is adhered to the spacer fabric. The substance can beadhered to the spacer fabric by any kind of chemical and/or physicalbonding.

A “liquid treating composition” as herein referred to means an emulsion,a solution or any other kind of liquid composition which can be used totreat a spacer fabric.

The provided liquid treating composition used in the method of theinvention preferably has a concentration of the C6-perfluoralkyl basedfluoropolymer(s) in the in the range of from 0.3 to 10 g/l, preferablyin the range of from 0.4 to 8 g/l, and most preferably in the range offrom 0.5 to 6 g/l. It is preferred that the liquid treating compositionis an aqueous liquid treating composition.

The provided spacer fabric is preferably free of perfluorooctanoic acid(PFOA), perfluorooctanesulfonic acid (PFOS) and perfluorooctanesulfonate (PFOS). “Free of” perfluorooctanoic acid,perfluorooctanesulfonic acid and perfluorooctane sulfonate means herethat the spacer fabric comprises not more than 1 ppm, preferably notmore than 100 ppb, most preferably not more than 10 ppb, of the sum ofperfluorooctanoic acid, perfluorooctanesulfonic acid and perfluorooctanesulfonate, based on of the total weight of the spacer fabric. Ifquestionable, it should be ensured that the spacer fabric provided isfree of perfluorooctanesulfonic acid, perfluorooctane sulfonate andperfluorooctanoic acid. “Being ensured to be free of”perfluorooctanesulfonic acid, perfluorooctane sulfonate andperfluorooctanoic acid means here that it has been actively ensured byappropriate measures that the provided spacer fabric indeed comprisesnot more than 1 ppm, preferably not more than 100 ppb, most preferablynot more than 10 ppb, of the sum of perfluorooctanoic acid,perfluorooctanesulfonic acid and perfluorooctane sulfonate, based on ofthe total weight of the spacer fabric. An appropriate measure in thiscontext can be a pre-washing step where the provided spacer fabric iswashed prior to step c). Alternatively, the provided spacer fabric canbe prefixed prior to step c). “Prefixing” means here that the providedspacer fabric is heated and, optionally, brought into uniform shape by,for example, stretching the spacer fabric. The heating may also lead toa reduction of any PFOA, PFOS and PFOS eventually present on theprovided spacer fabric.

The liquid treating composition is preferably free ofperfluorooctanesulfonic acid, perfluorooctane sulfonate andperfluorooctanoic acid. This means that the liquid treating compositioncomprises not more than 1 ppm, preferably not more than 100 ppb, mostpreferably not more than 10 ppb, of the sum of perfluorooctanoic acid,perfluorooctanesulfonic acid and perfluorooctane sulfonate, based on ofthe total weight of the liquid treating composition.

Beside the preferred absence of any PFOA and PFOS, of course, it is alsopreferred that both the provided spacer fabric and the liquid treatingcomposition are free of any C8-perfluoralkyl based fluoropolymers—due tothe environmental problems discussed above.

In the inventive method there is a step d) to remove excessive treatingcomposition from the treated spacer fabric. Excessive treatingcomposition can be removed, for example, by squeezing out the excessivetreating composition from the spacer fabric. Squeezing out can beperformed, for example, by nip-rolling the spacer fabric between tworubber rolls. Other methods of removing excessive treating compositioncan also be used. When removing excessive treating composition it isparticularly preferred that all of the removed treating composition—orat least a major part thereof—is separated from the bath containing theliquid treating composition which is used in step c) for treating thespacer fabric. This can be achieved, for example, by preventing at leasta major part or all of the removed treating composition from flowingback to the bath containing the liquid treating composition. A “majorpart” here means more than 40% by weight, preferably more than 50% byweight, even more preferably more than 60% by weight, and mostpreferably more than 70% by weight, of the removed treating composition.

As a result after removing excessive treating composition the so-called“pick-up” is preferably in the range of 50 to 150%, more preferably inthe range of 60 to 100%.

The “pick-up” as herein referred to is defined as the increase of weightof the wet treated spacer fabric after treatment with the treatingcomposition and after removing excessive treating composition comparedto the spacer fabric prior to the treatment. This means, if e.g. 100gram provided spacer fabric have a weight of 150 gram after beingtreated with the treating composition and after removing of excessivetreating composition the pick-up is 50%.

In a preferred method the excessive treating composition is removed fromthe spacer fabric by squeezing out between two rubber rolls. Thepressure between the two rubber rolls is preferably in the range of 1 to8 bar, more preferably in the range of 3 to 6 bar.

The advantage of separating the removed treating composition from thebath containing the liquid treating composition is that fiberpreparations washed out from the spacer fabric by excessive treatingcomposition does not accumulate in the bath containing the liquidtreating composition. This in turn prevents the spacer fabric immergedinto the bath for treatment from being contaminated with the accumulatedfiber preparations present in the bath. Contamination of the spacerfabric with accumulated fiber preparations present in the bath can be aproblem because the properties selected from flame retardancy, oilrepellency, spray rating and low volatile emissions can be negativelyaffected by the fiber preparations contamination, especially since suchfiber preparations contamination is typically inhomogeneous ornon-uniform.

“Fiber preparations” herein referred to are chemical substances nothaving an intended function at the final spacer fabric but which adhereto the provided spacer fabric as a result of the manufacture of thespacer fabric. Typical fiber preparations are lubricants and staticinhibitors. The chemical substances behind these lubricants and staticinhibitors are, for example, fats, waxes, oils and esters of phosphoricacid.

“Excessive treating composition” here means that amount or portion oftreating composition which is absorbed from or adhere to the spacerfabric after the treated spacer fabric has left the immerging bath butwhich is not needed, e.g. for achieving the desired properties, such asgood flame retardancy, good oil repellency, high spray rating and/or lowvolatile emissions, or which is just too much since it makes the treatedspacer fabric too wet for adequate or sound further processing.

In the inventive method there is a step e) of drying the treated spacerfabric. To “dry” a spacer fabric in context of the present inventionmeans that the spacer fabric is dried by means of, for example, warmingor heating the spacer fabric, by blowing warm or cold air over orthrough the spacer fabric or by irradiating the spacer fabric with e.g.IR-radiation or the like. The degree of “drying” or dryness is notcritical and depends on the desired properties of or the demands on thefinal spacer fabric.

In the inventive method there is a step 0 of fixing the treated spacerfabric. To “fix” a spacer fabric in context of the present inventionmeans that the treating composition adhered to the spacer fabric isfixed. This fixing is a process where as a result of temperature and/ortime and/or other causes the treating composition adhered to the spaceris hardened and/or aged and/or solidified and/or tempered and/or thelike. Fixing may also include a crosslinking process of theC6-perfluoralkyl based fluoropolymer(s) of the treating compositionand/or a covalent binding process of the C6-perfluoralkyl basedfluoropolymer(s) to the thermoplastic material of the spacer fabric.

In the inventive method there is prior to step c) an optional step ofpre-fixing the spacer fabric. To “pre-fix” a spacer fabric in context ofthe present invention means that the spacer fabric is brought intouniform shape by, for example, stretching and subsequently or at thesame time heating the spacer fabric. Pre-fixing by means of heating canalso be an alternative method to the optional pre-washing step of theprovided spacer fabric mentioned above in context with removing of anyPFOA, PFOS and PFOS eventually present on the provided spacer fabric.

The liquid treating composition used according to the present inventionpreferably comprises water as solvent and additionally one or moreemulsifier(s) or surfactant(s).

As emulsifier(s) or surfactant(s) non-ionic emulsifier/surfactantsis/are preferred. Polyoxyethylene glycol alkyl ethers andpolyoxypropylene glycol alkyl ethers are particularly preferred.

Additionally, further ingredients can be present in the liquid treatingcomposition, for example, alcohols like isopropanol as an auxiliaryagent.

In a preferred embodiment of the invention the liquid treatingcomposition comprises the C6-perfluoralkyl based fluoropolymer(s), theemulsifier(s), isopropanol and the water.

In a particularly preferred embodiment of the present invention theconcentration of fiber preparations in the liquid treating compositionin the bath is kept low as long as the treating step c) is performed.This means that it should be ensured—by appropriate measures—that theconcentration of fiber preparations in the liquid treating compositionin the bath is low, preferably as low as possible, when the spacerfabric is immerged into the bath of the liquid treating composition.

An “appropriate measure” for keeping the concentration of fiberpreparations in the bath of liquid treating composition low can be, forexample, ensuring that all or at least a major part of the removedtreating composition is separated from the bath containing the liquidtreating composition. The separation avoids accumulation of fiberpreparations which can be washed out from the spacer fabric by excessivetreating composition. Another measure for keeping the concentration offiber preparations low could be the dilution of “used” liquid treatingcomposition with fresh and uncontaminated liquid treating composition oreven—if a predetermined amount of fiber preparations contamination isreached—the substitution of “used” liquid treating composition withfresh and uncontaminated liquid treating composition.

It is also preferred according to the present invention that the spacerfabric provided in step a) comprises fiber preparations in an amount aslow as possible. Ideally, the provided spacer fabric is free of fiberpreparations. Therefore, and in order to achieve best results with thepresent invention, it should be ensured—by appropriate measures—that theprovided spacer fabric comprises fiber preparations in an amount as lowas possible or is essentially free of fiber preparations, at least whenentering the treating step c), i.e. when the spacer fabric is immerginginto the bath of the liquid treating composition.

An appropriate measure in this context can be a pre-washing step wherethe provided spacer fabric is washed prior to step c). Alternatively,the provided spacer fabric can be prefixed prior to step c). “Prefixing”means here that the provided spacer fabric is heated and, optionally,brought into uniform shape by, for example, stretching the spacerfabric.

As discussed above, is has surprisingly been found that the treatedspacer fabrics prepared according to the present inventive methodexhibit a good flame retardancy even if no additional flame retardantsare used when treating the spacer fabrics. This means, it is preferredthat no flame retardants are added to the provided liquid treatingcomposition and/or to the provided spacer fabric and/or to the treatedspacer fabric. It is particularly preferred that no flame retardants areadded at all to the provided liquid treating composition and to theprovided spacer fabric and to the treated spacer fabric.

“Flame retardants” in the sense of the present invention are theminerals, namely aluminium hydroxide, magnesium hydroxide, huntite andhydromagnesite, red phosphorus, and boron compounds; the organohalogencompounds, namely chlorendic acid derivatives and chlorinated paraffins,decabromodiphenyl ether, decabromodiphenyl ethane, brominatedpolystyrenes, brominated carbonate oligomers, brominated epoxyoligomers, tetrabromophthalic anyhydride, tetrabromobisphenol A andhexabromocyclododecane; the organophosphorus compounds, namelyorganophosphate, tris(2,3-dibromopropyl) phosphate, TPP, RDP, BPADP,tricresyl phosphate, phosphonates as DMMP and phosphinates.

The present invention is also directed to a treated spacer fabricobtainable by the method described above. In a preferred embodiment ofthe invention the treated spacer fabric obtainable by the methoddescribed above comprises at least a spacer fabric and about 0.03 toabout 1.0% by weight, preferably about 0.04 to about 0.8% by weight, andmost preferably in the range of from about 0.05 to about 0.6% by weight,of C6-perfluoralkyl based fluoropolymer(s), based on the weight of thespacer fabric. The amount of C6-perfluoralkyl based fluoropolymer(s) canbe determined according to the procedures described in DIN SPEC1038:2010. The person skilled in the art is able to identify and selectthose signals in the LC-MS (Liquid chromatography-mass spectrometry)measurements that origin from the C6-perfluoralkyl basedfluoropolymer(s) and to calibrate the measurements to obtain correctresults for the amount of C6-perfluoralkyl based fluoropolymer(s).Depending on the chosen procedural details of the procedures describedin DIN SPEC 1038:2010 a acceptable variation of the results may occur. Avariation of up to ±20% in the measured amount of the C6-perfluoralkylbased fluoropolymer(s) is acceptable within the present invention.

The spacer fabric obtainable by the method described above ispractically free of perfluorooctanoic acid (PFOA),perfluorooctanesulfonic acid (PFOS) and perfluorooctane sulfonate(PFOS). “Practically free of” perfluorooctanoic acid,perfluorooctanesulfonic acid and perfluorooctane sulfonate means herethat the spacer fabric comprises not more than 100 ppb, preferably notmore than 10 ppb, most preferably not more than 1 ppb, of the sum ofperfluorooctanoic acid, perfluorooctanesulfonic acid and perfluorooctanesulfonate, based on of the total weight of the spacer fabric.

More general, the present invention is directed to any treated spacerfabric comprising at least a spacer fabric and one or moreC6-perfluoralkyl based fluoropolymer(s), the treated spacer fabric beingfree of perfluorooctanesulfonic acid, perfluorooctane sulfonate andperfluorooctanoic acid and/or being free of any flame retardants. In apreferred embodiment of the invention the treated spacer fabriccomprises 0.03 to 1.0% by weight, preferably 0.04 to 0.8% by weight, andmost preferably in the range of from 0.05 to 0.6% by weight, of theC6-perfluoralkyl based fluoropolymer(s) based on the weight of thespacer fabric.

“Free of any flame retardants” means here that the spacer fabriccomprises less than 3% by weight, preferably less than 1% by weight,most preferably less than 0.1% by weight, of the sum of all flameretardants falling under the above definition, based on of the totalweight of the spacer fabric.

In a preferred embodiment of the invention the treated spacer fabric hasa velocity of burning (the most important criterion of flame retardancyaccording to FMVSS 302) of less than 100 mm/minute, preferably less than85 mm/minute, most preferably less than 70 mm/minute, in at least fiveof six measurements in cross direction, three measurements on the firstand three measurements on the second side, and has a total emissionaccording to VDA 277 (5 hours, 120° C.) of less than 100 μC/g,preferably less than 90 μC/g.

Preferably, and in addition to the above good velocity of burning andthe low total emission, the treated spacer fabric according to theinvention has a spraytest rating according to AATCC 22 of at least 70,preferably at least 75, most preferably at least 80.

Preferably, and in addition to the above good velocity of burning andthe low total emission and, optionally, good spray test rating, thetreated spacer fabric according to the invention has an oil repellencyrating according to AATCC 118 of at least 4, preferably at least 5, mostpreferably at least 6.

More preferably, and in addition to the above good velocity of burning,the low total emission and the optional good spray test rating and oilrepellency rating, the treated spacer fabric according to the inventionhas a fogging according to DIN 75201-B (16 hours, 100° C.) of less than100 mg, preferably less than 90 mg, most preferably less than 80 mg,and/or a smell according to VDA 270-2 (40° C.) of not worse than grade3, preferably of grade 2, most preferably of grade 1, and/or a emissionof formaldehyde according to VDA 275 of less than 3.0 mg/kg, preferablyless than 2.5 mg/kg, most preferably less than 2.0 mg/kg.

The present invention is also directed to the use of a liquid treatingcomposition comprising one or more C6-perfluoralkyl basedfluoropolymer(s) for preparing a treated spacer fabric of athermoplastic material, preferably a treated spacer fabric as describedabove in more detail. In a preferred embodiment of the invention theliquid treating composition comprises the C6-perfluoralkyl basedfluoropolymer(s) in a concentration range of from 0.3 to 10 g/l,preferably in the range of from 0.4 to 8 g/l, and most preferably in therange of from 0.5 to 6 g/l.

In a preferred embodiment of the invention the liquid treatingcomposition used as mentioned above preferably comprises water assolvent and additionally one or more emulsifier(s) or surfactant(s).

FIG. 1 shows a flow chart with the typical and preferred method stepswhen preparing a treated spacer fabric according to the invention. Oneor more of the steps of pre-fixing, removing, drying and fixing can beoptional if not needed for achieving customized requirements.

Examples Methods of Determining Selected Properties of the SpacerFabrics

The flame retardancy of the spacer fabrics has been measured accordingto FMVSS 302 (corresponds to DIN 75200). The total emission of thespacer fabrics has been measured according to VDA 277 (5 hours, 120°C.). The fogging of the spacer fabrics has been measured according toDIN 75201-B (16 hours, 100° C.). The smell of the spacer fabrics hasbeen measured according to VDA 270-2 (40° C.). The emission offormaldehyde of the spacer fabrics has been measured according to VDA275. The spraytest rating of the spacer fabrics has been measuredaccording to AATCC 22. The oil repellency rating of the spacer fabricshas been measured according to AATCC 118.

Method of Preparing the Treated Spacer Fabrics:

The untreated raw spacer fabrics are conducted via rolls through a bathcontaining the treating composition at a speed of 6 m/min whereby eachsection of the spacer fabrics is in contact with the treatingcomposition in the bath for about 3 to 5 seconds. The bath containingthe treating composition is heated to a temperature of 23° C. Thetreating composition is an aqueous emulsion containing about 2 gram perliter of a C6-perfluoralkyl based fluoropolymer (in form of BAYGARD EFNwhich is a liquid composition containing about 30% by weight of theC6-perfluoralkyl based fluoropolymer, BAYGARD EFN is available fromTanatex Chemicals B.V., Netherlands). After leaving the bath the spacerfabrics are conducted through two stainless steel rolls having aseparation distance of 0.2 mm for removing excessive treatingcomposition from the spacer fabrics. Discharge means are arranged belowthe rolls which separate the removed treating composition from the bathcontaining the liquid treating composition. Thereafter, the treatedspacer fabrics are dried with hot blowing air at a temperature of about165° C. Finally, the spacer fabrics are conducted through a devicefixing the treated spacer fabrics. The final treated spacer fabrics havebeen analyzed. The results are summarized in table 1.

TABLE 1 spacer fabric article 5944-3,4 (treated) 5944-3,4 (untreated)material unchanged polyester thickness unchanged 3,4 mm weight per unitarea 274.2 g/m² 273.1 g/m² (DIN EN 12127) velocity of burning 0 mm/min 0mm/min (one side, cross direction) 0 mm/min 54 mm/min 113 mm/min 0mm/min velocity of burning 0 mm/min 0 mm/min (other side, crossdirection) 80 mm/min 0 mm/min 61 mm/min 56 mm/min total emission 83.0μgC/g 72.0 μgC/g fogging 0.25 mg 0.85 mg smell grade 1 grade 1 emissionof formaldehyde 1.13 mg/kg 3.24 mg/kg oil repellency rating 6-7 —spraytest rating 80 —

TABLE 2 spacer fabric article 5977-3,7 (treated) 5977-3,7 (untreated)material unchanged polyester thickness unchanged 3,7 mm weight per unitarea 285.6 g/m² 284.5 g/m² (DIN EN 12127) velocity of burning 0 mm/min 0mm/min (one side, cross direction) 0 mm/min 0 mm/min 0 mm/min 0 mm/minvelocity of burning 0 mm/min 0 mm/min (other side, cross direction) 0mm/min 0 mm/min 0 mm/min 0 mm/min total emission 39.0 μgC/g 26.7 μgC/gfogging 0.6 mg 1.8 mg smell grade 2 grade 2 emission of formaldehyde 0.0mg/kg 0.4 mg/kg oil repellency rating 4-5 — spraytest rating 70-80 —

TABLE 3 spacer fabric article 5944-4,5 (treated) 5944-4,5 (untreated)material unchanged polyester thickness unchanged 4,5 mm weight per unitarea 298.2 g/m² 297.2 g/m² (DIN EN 12127) velocity of burning 76 mm/min84 mm/min (one side, cross direction) 0 mm/min 0 mm/min 0 mm/min 0mm/min velocity of burning 0 mm/min 0 mm/min (other side, crossdirection) 0 mm/min 80 mm/min 0 mm/min 74 mm/min total emission 8.4μgC/g 12.4 μgC/g fogging 0.4 mg 0.4 mg smell grade 1-2 grade 1-2emission of formaldehyde 0.0 mg/kg 0.0 mg/kg oil repellency rating  5 —spraytest rating 80 —

TABLE 4 spacer fabric article 9002-3,3 (treated) 9002-3,3 (untreated)material unchanged polyester thickness unchanged 3,3 mm weight per unitarea 255.9 g/m² 254.8 g/m² (DIN EN 12127) velocity of burning 0 mm/min 0mm/min (one side, cross direction) 0 mm/min 0 mm/min 0 mm/min 0 mm/minvelocity of burning 0 mm/min 0 mm/min (other side, cross direction) 0mm/min 0 mm/min 0 mm/min 0 mm/min total emission 2.0 μgC/g 4.0 μgC/gfogging 0.15 mg 0.4 mg smell grade 1-2 grade 1-2 emission offormaldehyde 0.0 mg/kg 0.0 mg/kg oil repellency rating  7 — spraytestrating 90 —

TABLE 5 spacer fabric article 9003-3,1 (treated) 9003-3,1 (untreated)material unchanged polyester thickness unchanged 3,1 mm weight per unitarea 211.2 g/m² 210.5 g/m² (DIN EN 12127) velocity of burning 0 mm/min 0mm/min (one side, cross direction) 0 mm/min 0 mm/min 0 mm/min 0 mm/minvelocity of burning 0 mm/min 0 mm/min (other side, cross direction) 0mm/min 0 mm/min 0 mm/min 0 mm/min total emission 1.6 μgC/g 8.0 μgC/gfogging 0.25 mg 0.45 mg smell grade 1-2 grade 1-2 emission offormaldehyde 0.0 mg/kg 0.0 mg/kg oil repellency rating  6 — spraytestrating 80 —

While this invention has been described as having a preferred design,the present invention can be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

1-15. (canceled)
 16. A method of preparing a treated spacer fabric,comprising the following steps: providing a spacer fabric of athermoplastic polymer; providing a liquid treating compositioncomprising at least one C6-perfluoralkyl based fluoropolymer(s) and asolvent; treating the spacer fabric by immerging the spacer fabric intoa bath of the liquid treating composition; removing excessive treatingcomposition from the treated spacer fabric; drying the treated spacerfabric; and fixing the treated spacer fabric.
 17. The method of claim16, wherein the thermoplastic polymer is selected from the groupconsisting of polyester, polyamide and a combination thereof.
 18. Themethod of claim 16, wherein the solvent is water and the liquid treatingcomposition additionally comprises at least one emulsifier.
 19. Themethod of claim 16, wherein, in at least one of said providing and saidtreating steps, no flame retardants are added.
 20. The method of claim16, wherein said removing step comprises separating at east a major partof the treating composition from the bath.
 21. The method of claim 16,wherein the concentration of the at least one C6-perfluoralkyl basedfluoropolymer in the provided liquid treating composition is 0.3 to 10g/l.
 22. The method of claim 16, wherein after said fixing step, thetreated spacer fabric is free of perfluorooctanesulfonic acid,perfluorooctane sulfonate, perfluorooctanoic acid, and flame retardants.23. The method of claim 16, wherein after said fixing step, the treatedspacer fabric has a velocity of burning according to FMVSS 302 of lessthan 100 min/minute in at least five of six measurements in crossdirection, three measurements on a first side and three measurements ona second side, and the treated spacer fabric has a total emissionaccording to VDA 277 of less than 100 μgC/g.
 24. The method of claim 16,wherein after said fixing step, the treated spacer fabric has at leastone of: a spray test rating according to AATCC 22 of at least 70; an oilrepellency rating according to AATCC 118 of at least 4; a foggingaccording to DIN 75201-B of less than 100 mg; a smell according to VDA270-2 of not worse than grade 3; and a emission of formaldehydeaccording to VDA 275 of less than 3.0 mg/kg.
 25. A treated spacerfabric, comprising: at least one spacer fabric; and at least oneC6-perfluoralkyl based fluoropolymer, the treated spacer fabric beingfree of perfluorooctanesulfonic acid, perfluorooctane sulfonate,perfluorooctanoic acid, and flame retardants.
 26. The treated spacerfabric of claim 25, wherein the treated spacer fabric has a velocity ofburning according to FMVSS 302 of less than 100 mm/minute in at leastfive of six measurements in cross direction, three measurements on afirst side and three measurements on a second side, and the treatedspacer fabric has a total emission according to VDA 277 of less than 100μgC/g.
 27. The treated spacer fabric of claim 25, wherein the treatedspacer fabric comprises 0.03 to 1.0% by weight of the at least oneC6-perfluoralkyl based fluoropolymer based on the weight of the spacerfabric.
 28. The treated spacer fabric of claim 25, wherein the treatedspacer fabric has at least one of: a spray test rating according toAATCC 22 of at least 70; an oil repellency rating according to AATCC 118of at least 4; a fogging according to DIN 75201-B of less than 100 mg; asmell according to VDA 270-2 of not worse than grade 3; a emission offormaldehyde according to VDA 275 of less than 3.0 mg/kg.